Microscopic origin of slow dynamics at the good glass forming composition range in Zr1−xCux metallic liquids

ABSTRACTThe viscosities of the Zr46.75Ti8.25Cu7.5Ni10Be27.5 and the Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk metallic glass forming liquids was determined from the melting point down to the glass transition in the entire temperature range of the supercooled liquid. The temperature dependence of the viscosity in the supercooled liquid obeys the Vogel-Fulcher-Tammann (VFT) relation. The fragility index D is about 20 for both alloys and the ratio between glass transition temperature and VFT temperature is found to be 1.5. A comparison with other glass forming systems shows that these bulk metallic glass formers are strong liquids comparable to sodium silicate glass. Furthermore, they are the strongest among metallic glass forming liquids. This behavior is a main contributing factor to the glass forming ability since it implicates a higher viscosity from the melting point down to the glass transition compared to other metallic liquids. Thus, the kinetics in the supercooled liquid is sluggish and yields a low critical cooling rate for glass formation. The relaxation behavior in the glass transition region of the alloys is consistent with their strong glassy nature as reflected by a stretching exponent that is close to 0.8. The microscopic origin of the strong liquid behavior of bulk metallic glass formers is discussed.

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Nanoshaping of glass forming metallic liquids by stretching: evading lithography

Nanotechnology ◽

10.1088/1361-6528/aaf3db ◽

2018 ◽

Vol 30 (7) ◽

pp. 075302 ◽

Cited By ~ 3

Author(s):

Zhonglue Hu ◽

Chandra Sekhar Meduri ◽

Jerzy Blawzdziewicz ◽

Golden Kumar

Keyword(s):

Glass Forming ◽

Metallic Liquids

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Linking Slow Dynamics and Local Structure in Simple Models of Glass-Forming Liquids

10.1063/1.2964559 ◽

2008 ◽

Author(s):

D. Coslovich ◽

G. Pastore ◽

Albert Co ◽

Gary L. Leal ◽

Ralph H. Colby ◽

...

Keyword(s):

Local Structure ◽

Slow Dynamics ◽

Glass Forming ◽

Simple Models

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Slow dynamics in glass-forming materials at α- and β-relaxation stages based on time-convolutionless mode-coupling theory

Physica A Statistical Mechanics and its Applications ◽

10.1016/j.physa.2019.121074 ◽

2019 ◽

Vol 526 ◽

pp. 121074

Author(s):

Michio Tokuyama

Keyword(s):

Mode Coupling ◽

Coupling Theory ◽

Mode Coupling Theory ◽

Slow Dynamics ◽

Glass Forming ◽

Β Relaxation ◽

Glass Forming Materials

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Bulk Glass-Forming Metallic Alloys: Science and Technology

MRS Bulletin ◽

10.1557/s0883769400053252 ◽

1999 ◽

Vol 24 (10) ◽

pp. 42-56 ◽

Cited By ~ 1962

Author(s):

William L. Johnson

Keyword(s):

Metallic Glasses ◽

Liquid Metals ◽

Rapid Quenching ◽

Metallic Alloys ◽

Bulk Glass ◽

Related Field ◽

Glass Forming ◽

Metallic Liquids ◽

Potential Applications ◽

Liquid Metal Alloy

The following article is based on the MRS Medal talk presented by William L. Johnson at the 1998 MRS Fall Meeting on December 2, 1998. The MRS Medal is awarded for a specific outstanding recent discovery or advancement that has a major impact on the progress of a materials-related field. Johnson received the honor for his development of bulk metallic glass-forming alloys, the fundamental understanding of the thermodynamics and kinetics that control glass formation and crystallization of glass-forming liquids, and the application of these materials in engineering.The development of bulk glass-forming metallic alloys has led to interesting advances in the science of liquid metals. This article begins with brief remarks about the history and background of the field, then follows with a discussion of multicomponent glass-forming alloys and deep eutectics, the chemical constitution of these new alloys, and how they differ from metallic glasses of a decade ago or earlier. Recent studies of deeply undercooled liquid alloys and the insights made possible by their exceptional stability with respect to crystallization will then be discussed. Advances in this area will be illustrated by several examples. The article then describes some of the physical and specific mechanical properties of bulk metallic glasses (BMGs), and concludes with some interesting potential applications.The first liquid-metal alloy vitrified by cooling from the molten state to the glass transition was Au-Si, as reported by Duwez at Caltech in 1960. Duwez made this discovery as a result of developing rapid quenching techniques for chilling metallic liquids at very high rates of 105–106 K/s.

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New Criterion for Prediction of Amorphous Alloy Compositions: A Сombination of Dense Packing of Spheres and the Lambda Criterion through the Coordination Number

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.698.411 ◽

2014 ◽

Vol 698 ◽

pp. 411-418 ◽

Cited By ~ 1

Author(s):

Carlos Ociran Silva Nascimento ◽

Alberto Moreira Jorge

Keyword(s):

Coordination Number ◽

Glass Formation ◽

Composition Range ◽

Dense Packing ◽

Phase Competition ◽

Glass Forming ◽

Instability Parameter ◽

New Criterion ◽

Crystallization Onset ◽

Good Agreement

This work presents the development of a new criterion which can indicate unknown compositions for amorphous metallic alloys. This new criterion was based on dense packing of spheres combined with the lambda criterion through the coordination number. A simplified mathematical development is presented, and software was developed with the purpose of indicating alloys with best glass forming ability (GFA). This software includes and concatenates several other criteria. For this purpose, we performed a mathematical analysis of the criteria, which included: (i) λ_min criterion which uses the minimum topological instability parameter and is used as an indication of phase competition during the solidification. (ii) the γ parameter, which reflects the relative GFA between bulk metallic glasses (BMG), and it is based on characteristic temperatures, such as: the glass transition temperature - Tg, the crystallization onset temperature - Tx and the liquidus temperature - Tl. (iii) the parameter Zc that is the critical thickness for bulk glass formation, which corresponds to the maximum dimension in which the molten can be formed without any crystals precipitation and (iv) the parameter Rc that is the critical cooling rate for glass formation, which decreases inversely to the Zc values. Through a mathematical formalism combining all the parameters, the software can decide the most suitable composition range to produce a new alloy. The results are presented and compared with the ones available in the literature. The results indicate good agreement with the literature since it is not a general theory, but intends to meet some specific cases with a reasonable convergence and which still need to be better studied.

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Bulk glass formation in the Ni–Zr–Ti–Nb–Si–Sn alloy system

Journal of Materials Research ◽

10.1557/jmr.2004.0286 ◽

2004 ◽

Vol 19 (8) ◽

pp. 2221-2225 ◽

Cited By ~ 36

Author(s):

J.Y. Lee ◽

D.H. Bae ◽

J.K. Lee ◽

D.H. Kim

Keyword(s):

Glass Formation ◽

Liquidus Temperature ◽

Eutectic Composition ◽

Composition Range ◽

Alloy System ◽

Glass Forming Ability ◽

Maximum Diameter ◽

Bulk Glass ◽

Glass Forming ◽

Crystallization Onset

In this study, the effect of addition of Nb on glass formation in Ni–Ti–Zr–Si–Sn alloys has been studied. The composition range for bulk glass formation with Dmax > 2 mm (Dmax, maximum diameter for glass formation by injection cast method) becomes wider when compared with the non-Nb–containing alloy. The ΔTx (= Tx – Tg; Tx, crystallization onset temperature; Tg, glass transition temperature), Trg (= Tg/Tl; Tl, liquidus temperature) and γ [= Tx/(Tl + Tg)] values for the alloys Dmax > 2 mm are in the range of 40–59, 0.638–0.651, and 0.410–0.419, respectively. The compositions of the alloys (Dmax > 2 mm) are closer to pseudo-eutectic composition than that of the alloy without Nb, showing an improved glass forming ability. The critical cooling rate for glass formation (Dmax = 5 mm) is estimated to be order of approximately 40 K/s.

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